Virgin Mobile is great. $25/month (well, more like $24 if you buy refill cards from a 3rd party like callingmart.com, and no taxes), 300 minutes, unlimited texts and data. Get the LG Optimus or Samsung Intercept (flash a modifed ROM to it and it runs great, kinda sluggish otherwise) and you get a pretty decent Android phone. And you can tether too :shifty eyes:
The only issue is coverage isn't fantastic, but if you stay on the beaten path (most cities/towns and on interstates) you'll do fine (I've only had no coverage a few times and I do a decent amount of traveling).
If you need coverage, and don't need unlimited data, Page Plus is great at $30/month for 1200 minutes, 2000 texts and 100MB of data. And you can bring your own verizon phone (except the iPhone or prepaid Verizon phones unless its been in service for at least 6 months).
I'm personally on the Virgin Mobile $25/month plan with a samsung intercept, wife is on pageplus (she talks a lot more than the 300 minutes that virgin mobile allots. And virgin mobile's $40/month is more expensive than pageplus) with a used Droid (got it for $70). Total monthly bill comes to $52.41, not bad at all.
Oh, and no contract so I can jump ship to another provider if one gives a better deal, and you can always port your phone number with you, so no issues there.
Seriously, just about the only reason to get a contract plan is to get the latest and greatest phone, and maybe better roaming terms. But that's about it, everything else is worse with a contract plan IMHO